def byte_calc(alist):
    newlist = []
    if sum(alist) != 0:
        for i in alist:
            if i != 0:
                newlist.append(i//2)
                newlist.append(i//3)
                newlist.append(i//4)
            else:
                newlist.append(i)
        return byte_calc(newlist)
    else:
        return len(alist)
    
print byte_calc([1000])
